<html lang="en">
<head>
<title>Empty Statements - GNU Compiler Collection (GCC) Internals</title>
<meta http-equiv="Content-Type" content="text/html">
<meta name="description" content="GNU Compiler Collection (GCC) Internals">
<meta name="generator" content="makeinfo 4.13">
<link title="Top" rel="start" href="index.html#Top">
<link rel="up" href="Statements.html#Statements" title="Statements">
<link rel="prev" href="Statement-Sequences.html#Statement-Sequences" title="Statement Sequences">
<link rel="next" href="Jumps.html#Jumps" title="Jumps">
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
<!--
Copyright (C) 1988-2015 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with the
Invariant Sections being ``Funding Free Software'', the Front-Cover
Texts being (a) (see below), and with the Back-Cover Texts being (b)
(see below). A copy of the license is included in the section entitled
``GNU Free Documentation License''.
(a) The FSF's Front-Cover Text is:
A GNU Manual
(b) The FSF's Back-Cover Text is:
You have freedom to copy and modify this GNU Manual, like GNU
software. Copies published by the Free Software Foundation raise
funds for GNU development.-->
<meta http-equiv="Content-Style-Type" content="text/css">
<style type="text/css"><!--
pre.display { font-family:inherit }
pre.format { font-family:inherit }
pre.smalldisplay { font-family:inherit; font-size:smaller }
pre.smallformat { font-family:inherit; font-size:smaller }
pre.smallexample { font-size:smaller }
pre.smalllisp { font-size:smaller }
span.sc { font-variant:small-caps }
span.roman { font-family:serif; font-weight:normal; }
span.sansserif { font-family:sans-serif; font-weight:normal; }
--></style>
</head>
<body>
<div class="node">
<a name="Empty-Statements"></a>
<p>
Next: <a rel="next" accesskey="n" href="Jumps.html#Jumps">Jumps</a>,
Previous: <a rel="previous" accesskey="p" href="Statement-Sequences.html#Statement-Sequences">Statement Sequences</a>,
Up: <a rel="up" accesskey="u" href="Statements.html#Statements">Statements</a>
<hr>
</div>
<h4 class="subsection">10.7.4 Empty Statements</h4>
<p><a name="index-Empty-Statements-1940"></a>
Whenever possible, statements with no effect are discarded. But
if they are nested within another construct which cannot be
discarded for some reason, they are instead replaced with an
empty statement, generated by <code>build_empty_stmt</code>.
Initially, all empty statements were shared, after the pattern of
the Java front end, but this caused a lot of trouble in practice.
<p>An empty statement is represented as <code>(void)0</code>.
</body></html>